title: Poly(A) tail-mediated gene regulation by opposing roles of Nab2 and Pab2 nuclear poly(A)-binding proteins in pre-mRNA decay.
abstract: The 3' end of most eukaryotic transcripts is decorated by poly(A)-binding proteins (PABPs), which influence the fate of mRNAs throughout gene expression. However, despite the fact that multiple PABPs coexist in the nuclei of most eukaryotes, how functional interplay between these nuclear PABPs controls gene expression remains unclear. By characterizing the ortholog of the Nab2/ZC3H14 zinc finger PABP in Schizosaccharomyces pombe, we show here that the two major fission yeast nuclear PABPs, Pab2 and Nab2, have opposing roles in posttranscriptional gene regulation. Notably, we find that Nab2 functions in gene-specific regulation in a manner opposite to that of Pab2. By studying the ribosomal-protein-coding gene rpl30-2, which is negatively regulated by Pab2 via a nuclear pre-mRNA decay pathway that depends on the nuclear exosome subunit Rrp6, we show that Nab2 promotes rpl30-2 expression by acting at the level of the unspliced pre-mRNA. Our data support a model in which Nab2 impedes Pab2/Rrp6-mediated decay by competing with Pab2 for polyadenylated transcripts in the nucleus. The opposing roles of Pab2 and Nab2 reveal that interplay between nuclear PABPs can influence gene regulation.
authors.affiliation: RNA Group, Université de Sherbrooke, Department of Biochemistry, Québec, Canada.
authors.forename: Valérie
authors.initials: V
authors.lastname: Grenier St-Sauveur
authors.forename: Sharon
authors.initials: S
authors.lastname: Soucek
authors.forename: Anita H
authors.initials: AH
authors.lastname: Corbett
authors.forename: François
authors.initials: F
authors.lastname: Bachand
mesh_terms: D000595:Amino Acid Sequence; D017124:Conserved Sequence; D063326:Exosome Multienzyme Ribonuclease Complex / Q000378:metabolism; D015966:Gene Expression Regulation, Fungal; D055786:Gene Knockout Techniques; D008969:Molecular Sequence Data; D039102:Poly(A)-Binding Proteins / Q000502:physiology*; D026723:Polyadenylation; D012322:RNA Precursors / Q000235:genetics / Q000378:metabolism; D020871:RNA Stability; D012333:RNA, Messenger / Q000235:genetics / Q000378:metabolism*; D016601:RNA-Binding Proteins / Q000737:chemistry / Q000502:physiology*; D000090822:Ribosomal Protein L3; D012269:Ribosomal Proteins / Q000235:genetics / Q000378:metabolism; D012568:Schizosaccharomyces / Q000235:genetics / Q000378:metabolism*; D029702:Schizosaccharomyces pombe Proteins / Q000737:chemistry / Q000502:physiology*
chemical_list: C579779:Nab2 protein, S pombe; C582314:Pab2 protein, S pombe; D039102:Poly(A)-Binding Proteins; D012322:RNA Precursors; D012333:RNA, Messenger; D016601:RNA-Binding Proteins; D000090822:Ribosomal Protein L3; D012269:Ribosomal Proteins; D029702:Schizosaccharomyces pombe Proteins; D063326:Exosome Multienzyme Ribonuclease Complex